Ford is keeping its sixth-generation Explorer SUV well under wraps until its debut.

This is the all-new Ford Explorer – though you might not be able to tell just by looking at it. Underneath all that heavy cladding sits a brand new platform, and eventually a range of new engine options. The mule was caught testing again on public roads near Dearborn, Michigan, this past week.

Update:

The new D6 platform will replace the outgoing D4 platform – which has been on the market since 2005 – and is expected to underpin not only the Explorer but also the new Lincoln MKT. It can be configured in either front-, rear-, or all-wheel-drive, depending on the spec, though the prototype seen here seems to be putting to use the former, as no rear axle is present.

Under the hood, a range of more efficient engine options will be offered. The existing 2.3-liter four-cylinder, and 3.5-liter V6 EcoBoost will remain, but the naturally-aspirated 3.5-liter V6 could be axed in place of something more mpg friendly. No word on whether the same six-speed automatic transmission will carry over, or if the Explorer will gain the new 10-speed automatic proposed for the Mustang.

The Explorer, which has been on the market since 1990, has been a mainstay vehicle for Ford, with more than seven million examples sold in the United States alone. The current fifth-generation model, which has been on the market since 2011, has been marginally successful, earning the North American Truck of the Year Award in 2011.

The sixth generation of the seven-seat SUV is expected to debut either at the 2017 Los Angeles Auto Show or the 2018 Detroit Auto Show. It will go on sale sometime in summer 2018 as a 2019 model.